Adjustable pressure devices for double endless tape sliver draft units



March 1, 1960 A. GARDELLA 2,926,393 ADJUSTABLE PRESSURE DEVICES FOR DOUBLE ENDLESS TAPE SLIVER DRAFT UNITS 2 Sheets-Sheet 1 Filed March 15, 1957 A'I'I' RNEY March 1, 1960 A. GARDELLA 2,926,393

ADJUSTABLE PRESSURE DEVICES FOR DOUBLE ENDLESS TAPE SLIVER DRAFT UNITS Filed March 15, 1957 2 Sheets-Sheet 2 I INVENTOR /4m//wo 634 805444 United States Patent ADJUSTABLE PRESSURE DEVICES FOR DOUBLE ENDLESS 'IAPE SLIVER DRAFT UNITS V Adriano Gardella, Genoa, Italy I Application March 15, 1951, Serial No. 646,454

Claims priority, application Italy March 15, 1956 4 Claims. (Cl. 19-135 The present invention has for its object a double endless tape draft unit, particularly for strands or. slivers of long and hard fibres such as hemp, flax, jute, sisal and the like.-

In these drafting units, between the feed and the delivery roller pairs, a pair of endless tapes or bands is fitted having two adjacent runs, which run in the same direction and between which the fibre sliver passes. Thus:

the sliver is supported during the whole drafting operation and thus a high and -very high sliver attenuation (high drafting) maybe attained. o

In the high and very high drafting units, provided with endless tapes, the adjacent or inside runs of which are pressed against each otherby compression members, it is often necessary or desirable to adjust either the position of the pressure means or/ and the amount of pressure on the inside or contacting tape runs, these adjustments being possibly efiected separately and independently from one another.

According to the invention, this end is attained in a very simple and practical manner by mounting the pressure member or members shiftable both in longitudinal direction with respect to the inside or active run of one of the endless tapes and towards and away from said tape.

Still according to a preferred constructive form, the pressure member or members is or are slidable in longitudinal direction with respect to the tape, on any suitable guide whatsoever which in its turn is mounted either swinging or slidable away and towards the co-acting sections of the tapes, means being provided for controlling both the sliding of the pressure member-carrying parts as well as for controlling the shiftings of the guide. The said pressure member may be constructed either in the form of a convex slide, having its convex part turned towards the co-acting sections of. the tapes, or also may comprise one or a plurality of rotatable rollers, reducing the friction on the tape and enabling more accurate adjustment of the contact point or points thereof with the endless tape.

According to another preferred embodiment of the invention the tape-compressing device comprises a swinging arm carrying the pressure member or members which is or are slidable with regards to the hinge point of said arm, are urged by a spring in one direction and may be pulled by means of a flexible cord or cable in the opposite direction.

The compact construction of this device and the possibility of controlling same by means of a flexible cord is a particular advantage in the spinning frames in which the arrangement of the tape-compressing device and of its controlling means presents serious difliculties due to lack of space.

The invention will be better understood from the following specification taken in connection with the annexed drawings, in which:

I Figure 1 shows in elevation a double tape sliver draft unit.

.Figure 2 is a plan view of the tape-pressing device, viewed from the arrows IIII of Figure 1, and

Figure 3 is a section on line IIIIII of Figure 1.

In the figures, 1 and 101 are the feed rollers and 2, 102 the delivery rollers of a drafting unit forming part, for example, of a spinning frame.

Between the pair of feed rollers 1, 101 and of the delivery rollers 2, 102 run two endless tapes 5, 6 which are mounted on two pairs of pulleys 3, 4 and have two contacting runs 105, 106 which are driven in the same direction. The fibre sliver to be drawn (not shown), is guided, between these contacting runs and 106 of said endless tapes and is thus wholly supported during the drafting.

Between the upper pulley 3 and the lower pulley 4 of one of the tapes 6, namely in proximity of the upper pulley 3, on the machine frame 7 a pivot 8 is fastened with its axis parallel to the axes of the said pulleys 3, 4. On this pivot 8 a hub 9 provided with a tubular arm 10 is mounted so as to swing freely. Said arm 10 extends between;the two runs of the tape 6 and terminates with an arcuate bracket-like extension 11 which projects sidewise from the tapes pair 5, 6 and its end, which lies outside of said tapes, is connected by means of a link 12 to a crank 13 fastened on a shaft 14 and the angular position of which may be adjusted by hand by some conventional means (not shown), thus varying the angular position of the arm 10 with respect to the tape run 106.

In the tubular arm 10 is slidably mounted like a telescope a rod 15, which is pushed outwardly by a spring 17 and carries at its free end a pair of rollers 16 rotatably mounted on a pivot 20 the axis of which is parallel to the axis of the pulleys 3, 4.

By suitably adjusting the angular position of the arm 10, these rollers are pressed more or less against the run 106 of the tape 6 which is thus pressed with a more or less great force against the fibre sliver passing between the tape runs 106 and 105. The slidable rod 15 is held against the force of the spring 17 by two flexible cords or cables 19 attached to a cross member 1'8 at the lower free end of rod 15. The cords 19 pass on two small grooved pulleys 21 rotatably mounted to both sides of the hub 9 and are fastened at 23 to a split sleeve 24 or the like, fastened onto a small shaft 22. By rotating the shaft 22, the cords 19 are pulled more or less, thus varying the amount of projection of the rod 15 from the tubular arm 10 and consequently the position of the rollers on the tape run 106.

From the foregoing it is apparent that the just described device permits to vary at will the compression force of the rollers 16 against the tape run 106 in order to adjust same to the requirements of the different fibre kinds, to the different fibre sliver thicknesses and to the drafting ratios, this latter end being attained by adjusting the angular position of the arm 10. The bearing point of the rollers against the tape run 106 may be adjusted by rotating the shaft 22 so as to draw more or less the cords 19 which pull the rod 15 in the direction of the pivot 8 of the tubular arm 10.

I claim:

1. In a sliver draft unit of the kind comprising a pair of endless tapes arranged with their inner runs adjacent and substantially parallel and running in the same direction, between which the sliver to be attenuated passes, the arrangement between the two runs of either of said endless tapes of an arm swinging substantially along the plane of said endless belts and provided with a telescoping part; the corresponding inside belt run carrying at its end pressure means adapted to bear with a certain pressure against spring means urging said telescoping part outwardly; a cord attached by one of its ends to said telescoping means and anchored by its other end to a Patented Mar. 1, 1960 control means which is adapted to be operated so-as'to pull said cord and shift said telescoping means in pposition to the said spring means; an extension of the non-telescoping part of said swinging arm'projecting outside of said belt and carrying a pin; a crank pin whose angular position may be adjusted at will and a link hinged by one of its ends to said crank pin and by itsother end to the pin fitted at the end of said arm extension.

2. A sliver draft unit accordingto claim 1, in which the said pressure means comprisea number of rollers rotatably mounted on pivots fitted at the end of said telescoping arm. a

3. In a sliver draft unit of the type including a pair of endless tapes arranged with their inner runs adjacent and substantially parallel and running in the same direction, the combination of pressure means disposed between the two runs of one of said endless tapes to press the inner run of said one endless tape against the inner run of the other endless tape of the pair, means mounting said pressure means for continuously 'shiftable' movement along the length of said inner tape'run, means supporting said mounting means for movement toward and from said inner tape run for varying the amount of pressure by said pressure means against said inner tape ru'n', said mounting means including carrier means for said pressure means and arm means slidably supporting said carrier means, pivot means mounted between the tape run's and swingably supporting said arm means, means for urging said carrier means relative to said arm means in' one direction, means controlled from the exterior of said unit for moving said carrier means in an opposite direction, and said supporting means comprising control means 3 two runs or one of said endless tapes to press the inner run of said one endless tape against the inner run of the other endless tape of the pair, means mounting said pressure means for continuously shiftable movement along the length of said inner tape run, means sup ortin said mounting means for movement toward and from said inner tape run for varying the amount of pressure by said pressure means againstsaid inner tape run, said mounting means including a telescoping arm, pivot means swingably supporting one telescoping portion of said arm,

' another telescoping portion of said arm supporting said pressure means, spring means urging the telescoping" portions of said arm relatively in one direction, means con trolled from-the exterior for moving said telescoping arm portions relatively in an opposite direction, and said supporting'means including control means for adjusting the angular position of said swinging arm with respect to the inner run of said endless tape.

Referen'cesCited in the file of this patent UNITED STATES PATENTS 109,430 I Leavitt Nov. 22, 1870 2,239,863 Schlipp Apr. 29, 1941 2,623,346 Lohfert et al. a Dec. 30, 1952 

